x+4y=2(1)

x=3-4y(2)

What are the (1) and (2) ???

ignoring them I assume you have two linear equations in x and y
rewrite these as
x + 4 y = 2
x + 4 y = 3
this set of equations is inconsistent. the same quantity can not be both 2 and 3.
In fact these are two parallel lines on a graph and never cross.
here is no solution.

4w+x+2y-3z=-16, -3w+3x-y+4z=20, -w+2x+5y+z=-4, 5w+4x+3y-z=-10

To solve this system of equations, you can use the method of substitution. Let's start by rearranging equation (2) to solve for x.

From equation (2), we have:

x = 3 - 4y

Now, we can substitute this value of x into equation (1).

Replace x in equation (1) with its equivalent expression from equation (2):

(3 - 4y) + 4y = 2

Simplify the left-hand side of the equation:

3 - 4y + 4y = 2

Combine like terms:

3 = 2

Since this is not a true statement, it means that there is no solution to this system of equations. The equations are inconsistent.